1. Field of the Invention
The invention relates to a power transmitting device, a vehicle, and a contactless power transfer system, and more particularly, to a pairing technology between a power transmitting device and a vehicle in a contactless power transfer system.
2. Description of Related Art
Contactless wireless power transmission that does not use a power cord or a power transmitting cable has recently been drawing attention. It has been proposed to apply this contactless wireless power transfer to an electric vehicle, a hybrid vehicle or the like in which an in-vehicle electrical storage device can be charged by a power supply outside the vehicle (hereinafter referred to also as “an external power supply”).
In contactless power transmission, it is necessary to appropriately carry out recognition (pairing) between a power transmitting device and a power receiving device.
According to an art disclosed in Japanese Patent Application Publication No. 2007-19719 (JP-2007-19719 A), in a system that is equipped with a portable terminal device, and an anti-theft portable radio communication unit for recognizing a user of the portable terminal device, it is determined, on the basis of a signal from a radio frequency identification (an RFID) that is provided in the radio communication unit, that the portable terminal device to be recognized is within a specific area.
In a contactless power transfer system that supplies power to a vehicle in a contactless manner, information is exchanged between a vehicle and a power transmitting device through radio communication, and pairing is carried out with parties exchanging power recognized by each other. In such a system, it is necessary to establish communication with a plurality of vehicles or a plurality of power transmitting devices. In general, therefore, radio communication having a relatively wide communicable area is used.
However, in the case where such wide area radio communication is used, pairing may be carried out with a vehicle that is different from a vehicle to be actually supplied with power. In the case where pairing between the vehicle and the power transmitting device is not correctly carried out, the vehicle to be supplied with power may not be appropriately supplied with power from the power transmitting device.